Agricultural-Waste-Derived Wound Patch for Enhanced Healing of Cutaneous Leishmaniasis Wounds

Introduction: The World Health Organization has raised the alarm concerning the burden of cutaneous leishmaniasis (CL), which mainly affects poor marginalized communities globally, causing non-healing ulcerated wounds that leave stigmatizing scars. Secondary bacterial infections highly hinder the healing process, making patients more vulnerable to other diseases. This study aims to develop wound dressings that accelerate healing while preventing secondary infections using sugarcane bagasse lignocellulosic biomass, which is abundant in Mauritius. This approach shifts the focus from merely eradicating Leishmania parasites to improving wound healing in CL patients.

Methods: Cellulose and lignin were extracted using a single cost-effective protocol, blended in varying ratios and chemically crosslinked to form soft hydrogels (Cel-lig). Their physicochemical properties, biocompatibility with murine cells and antibacterial activity were evaluated. The optimal hydrogel was then loaded with eugenol (EUG) and berberine (BER), respectively, to enhance its biological activities. The in vitro biocompatibility of the loaded scaffolds was tested with mouse fibroblasts (L929) and macrophages (RAW 264.7), and the production of a pro-inflammatory cytokine (TNF-α) was determined. Additionally, the antibacterial activity of the loaded hydrogels was tested against a representative of the common bacteria isolated from CL wounds.

Results and Discussion: The Cel-lig 70:30 hydrogel possessed adequate surface stiffness for the adhesion and migration of the L929 cells in vitro and antibacterial activity owing to lignin’s intrinsic antimicrobial properties. Loading of EUG and BER into Cel-lig 70:30 did not alter the hydrogel’s physicochemical characteristics. The hydrogels did not trigger high production levels of TNF-α from the RAW 264.7 macrophages and showcased significant antibacterial activity against Gram-positive and Gram-negative bacteria, with the 24-hour growth reduction percentages ranging from 61 to 79%.

Conclusion: Among all the hydrogels tested, the Cel-lig 70:30 hydrogels loaded with eugenol and berberine, respectively, demonstrated the best attributes for advanced testing and for conversion into a wound patch for direct use on CL wounds.